DESCRIPTION (provided by candidate): Gene regulatory mechanisms that assign and maintain motor neuron terminal differentiation Summary: Defects in motor neuron (MN) function or survival result in severe human conditions such as amyotrophic lateral sclerosis (ALS), and spinal muscular atrophy (SMA). There are no effective treatments for MN disorders in part due to our poor understanding of the last steps of MN development, i.e., the induction of MN terminal differentiation genes. In addition, the molecular mechanisms that maintain the expression of MN terminal differentiation genes during adult life (and thereby ensure MN function) are largely unknown. We have recently provided the first insights on the regulatory mechanisms that establish MN terminal differentiation during development and maintain it in adult life. Using a nematode and a simple chordate as model systems, we showed that the COE (Collier, Olf, Ebf) family of transcription factors assigns and maintains MN terminal differentiation. In this Career Development Proposal, C In Aim #1, I will test the hypothesis that Ebf2 (COE family member) is required for terminal differentiation of spinal MNs using my expertise in conditional mouse mutagenesis. The goal of Aim #2 is to identify novel MN terminal differentiation markers in vertebrates using ChIP-sequencing and microarray technology on mouse embryonic stem cell (mESC)-derived MNs. This is a much-anticipated goal in the MN field as currently only the acetylcholine (ACh) pathway genes serve as bona fide markers of MN terminal differentiation. In Aim #3, I will aim to reveal other evolutionarily conserved transcripton factors that are required for terminal differentiation of specific MN subtypes in C. Elegans. The knowledge gained from these aims will lend to our understanding of how MN terminal differentiation is established during development and maintained throughout life, and may provide novel entry points into the etiology, diagnosis or treatment of MN disorders. If funded, this Career development Award (CDA) would afford me the opportunity to expand my background in C. Elegans genetics, develop additional expertise in vertebrate neurobiology, obtain the necessary training in ChIP-sequencing and the use of bioinformatic tools; skills critical for my future success as an independent researcher. Formal and informal interactions with my Advisory Committee will assess my progress on the proposed Aims and provide advice. Finally, professional skills (e.g. mentoring, research presentation, time management) vital to my long-term success as an academic will be gained during the K99 phase through Columbia University courses and advice by my advisory committee and my mentor. Together, the proposed studies and career development plan will ensure I achieve my long-term goal; to establish a successful laboratory at a major University and make significant contributions to the MN field.